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Filsfils, Ed. 3 Internet-Draft S. Previdi, Ed. 4 Intended status: Standards Track A. Bashandy 5 Expires: April 23, 2014 Cisco Systems, Inc. 6 B. Decraene 7 S. Litkowski 8 Orange 9 M. Horneffer 10 Deutsche Telekom 11 I. Milojevic 12 Telekom Srbija 13 R. Shakir 14 British Telecom 15 S. Ytti 16 TDC Oy 17 W. Henderickx 18 Alcatel-Lucent 19 J. Tantsura 20 Ericsson 21 E. Crabbe 22 Google, Inc. 23 October 20, 2013 25 Segment Routing interoperability with LDP 26 draft-filsfils-spring-segment-routing-ldp-interop-00 28 Abstract 30 A Segment Routing (SR) node steers a packet through a controlled set 31 of instructions, called segments, by prepending the packet with an SR 32 header. A segment can represent any instruction, topological or 33 service-based. SR allows to enforce a flow through any topological 34 path and service chain while maintaining per-flow state only at the 35 ingress node to the SR domain. 37 The Segment Routing architecture can be directly applied to the MPLS 38 data plane with no change in the forwarding plane. This drafts 39 describes how Segment Routing operates in a network where LDP is 40 deployed and in the case where SR-capable and non-SR-capable nodes 41 coexist. 43 Requirements Language 45 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 46 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 47 document are to be interpreted as described in RFC 2119 [RFC2119]. 49 Status of this Memo 51 This Internet-Draft is submitted in full conformance with the 52 provisions of BCP 78 and BCP 79. 54 Internet-Drafts are working documents of the Internet Engineering 55 Task Force (IETF). Note that other groups may also distribute 56 working documents as Internet-Drafts. The list of current Internet- 57 Drafts is at http://datatracker.ietf.org/drafts/current/. 59 Internet-Drafts are draft documents valid for a maximum of six months 60 and may be updated, replaced, or obsoleted by other documents at any 61 time. It is inappropriate to use Internet-Drafts as reference 62 material or to cite them other than as "work in progress." 64 This Internet-Draft will expire on April 23, 2014. 66 Copyright Notice 68 Copyright (c) 2013 IETF Trust and the persons identified as the 69 document authors. All rights reserved. 71 This document is subject to BCP 78 and the IETF Trust's Legal 72 Provisions Relating to IETF Documents 73 (http://trustee.ietf.org/license-info) in effect on the date of 74 publication of this document. Please review these documents 75 carefully, as they describe your rights and restrictions with respect 76 to this document. Code Components extracted from this document must 77 include Simplified BSD License text as described in Section 4.e of 78 the Trust Legal Provisions and are provided without warranty as 79 described in the Simplified BSD License. 81 Table of Contents 83 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 84 2. SR/LDP Ship-in-the-night coexistence . . . . . . . . . . . . . 4 85 2.1. MPLS2MPLS co-existence . . . . . . . . . . . . . . . . . . 6 86 2.2. IP2MPLS co-existence . . . . . . . . . . . . . . . . . . . 7 87 3. Migration from LDP to SR . . . . . . . . . . . . . . . . . . . 7 88 4. SR and LDP Interworking . . . . . . . . . . . . . . . . . . . 8 89 4.1. LDP to SR . . . . . . . . . . . . . . . . . . . . . . . . 8 90 4.2. SR to LDP . . . . . . . . . . . . . . . . . . . . . . . . 9 91 5. Leveraging SR benefits for LDP-based traffic . . . . . . . . . 10 92 5.1. Eliminating Directed LDP Session . . . . . . . . . . . . . 12 93 5.2. Guaranteed FRR coverage . . . . . . . . . . . . . . . . . 12 94 6. Inter-AS Option C, Carrier's Carrier and Seamless MPLS . . . . 14 95 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 96 8. Manageability Considerations . . . . . . . . . . . . . . . . . 14 97 9. Security Considerations . . . . . . . . . . . . . . . . . . . 14 98 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14 99 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 100 11.1. Normative References . . . . . . . . . . . . . . . . . . . 15 101 11.2. Informative References . . . . . . . . . . . . . . . . . . 15 102 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 104 1. Introduction 106 Segment Routing, as described in 107 [I-D.filsfils-rtgwg-segment-routing], can be used on top of the MPLS 108 data plane without any modification as described in 109 [draft-filsfils-rtgwg-segment-routing-mpls-00]. 111 Segment Routing control plane can co-exist with current label 112 distribution protocols such as LDP. 114 This draft outlines the mechanisms through which SR provides 115 interoperability with LDP in cases where a mix of SR-capable and non- 116 SR-capable routers co-exist within the same network. 118 The first section describes the co-existence of SR with other MPLS 119 Control Plane. The second section documents a method to migrate from 120 LDP to SR-based MPLS tunneling. The third section documents the 121 interworking of LDP and SR in the case of non-homogenous deployment. 122 The fourth section describes how a partial SR deployment can be used 123 to provide SR benefits to LDP-based traffic. The fifth section 124 describes a possible application of SR in the context of inter-domain 125 MPLS use-cases. 127 2. SR/LDP Ship-in-the-night coexistence 129 We call "MPLS Control Plane Client (MCC)" any control plane protocol 130 installing forwarding entries in the MPLS data plane. SR, LDP, 131 RSVP-TE, BGP 3107, VPNv4, etc. are examples of MCCs. 133 An MCC, operating at node N, must ensure that the incoming label it 134 installs in the MPLS data plane of Node N has been uniquely allocated 135 to himself. 137 Thanks to the defined segment allocation rule and specifically the 138 notion of the SRGB, SR can co-exist with any other MCC. 140 This is clearly the case for the adjacency segment: it is a local 141 label allocated by the label manager, as for any MCC. 143 This is clearly the case for the prefix segment: the label manager 144 allocates the SRGB set of labels to the SR MCC client and the 145 operator ensures the unique allocation of each global prefix segment/ 146 label within the allocated SRGB set. 148 Note that this static label allocation capability of the label 149 manager has been existing for many years across several vendors and 150 hence is not new. Furthermore, note that the label-manager ability 151 to statically allocate a range of labels to a specific application is 152 not new either. This is required for MPLS-TP operation. In this 153 case, the range is reserved by the label manager and it is the 154 MPLS-TP NMS (acting as an MCC) that ensures the unique allocation of 155 any label within the allocated range and the creation of the related 156 MPLS forwarding entry. 158 Let us illustrate an example of ship-in-the-night (SIN) coexistence. 159 PE2 PE4 160 \ / 161 PE1----A----B---C---PE3 163 Figure 1: SIN coexistence 165 The EVEN VPN service is supported by PE2 and PE4 while the ODD VPN 166 service is supported by PE1 and PE3. The operator wants to tunnel 167 the ODD service via LDP and the EVEN service via SR. 169 This can be achieved in the following manner: 171 The operator configures PE1, PE2, PE3, PE4 with respective 172 loopbacks 192.0.2.201/32, 192.0.2.202/32, 192.0.2.203/32, 173 192.0.2.204/32. These PE's advertised their VPN routes with next- 174 hop set on their respective loopback address. 176 The operator configures A, B, C with respective loopbacks 177 192.0.2.1/32, 192.0.2.2/32, 192.0.2.3/32. 179 The operator configures PE2, A, B, C and PE4 with SRGB {100, 300}. 181 The operator attaches the respective Node-SIDs 202, 101, 102, 103 182 and 204 to the loopbacks of nodes PE2, A, B, C and PE4. The Node- 183 SID's are configured to request penultimate-hop-popping. 185 PE1, A, B, C and PE3 are LDP capable. 187 PE1 and PE3 are not SR capable. 189 PE3 sends an ODD VPN route to PE1 with next-hop 192.0.2.203 and VPN 190 label 10001. 192 From an LDP viewpoint: PE1 received an LDP label binding (1037) for 193 FEC 192.0.2.203/32 from its nhop A. A received an LDP label binding 194 (2048) for that FEC from its nhop B. B received an LDP label binding 195 (3059) for that FEC from its nhop C. C received implicit-null LDP 196 binding from its next-hop PE3. 198 As a result, PE1 sends its traffic to the ODD service route 199 advertised by PE3 to next-hop A with two labels: the top label is 200 1037 and the bottom label is 10001. A swaps 1037 with 2048 and 201 forwards to B. B swaps 2048 with 3059 and forwards to C. C pops 3059 202 and forwards to PE3. 204 PE4 sends an EVEN VPN route to PE2 with next-hop 192.0.2.204 and VPN 205 label 10002. 207 From an SR viewpoint: PE1 maps the IGP route 192.0.2.204/32 onto 208 Node-SID 204; A swaps 204 with 204 and forwards to B; B swaps 204 209 with 204 and forwards to C; C pops 204 and forwards to PE4. 211 As a result, PE2 sends its traffic to the VPN service route 212 advertised by PE4 to next-hop A with two labels: the top label is 204 213 and the bottom label is 10002. A swaps 204 with 204 and forwards to 214 B. B swaps 204 with 204 and forwards to C. C pops 204 and forwards to 215 PE4. 217 The two modes of MPLS tunneling co-exist. 219 The ODD service is tunneled from PE1 to PE3 through a continuous 220 LDP LSP traversing A, B and C. 222 The EVEN service is tunneled from PE2 to PE4 through a continuous 223 SR node segment traversing A, B and C. 225 2.1. MPLS2MPLS co-existence 227 We want to highlight that several MPLS2MPLS entries can be installed 228 in the data plane for the same prefix. 230 Let us examine A's MPLS forwarding table as an example: 232 Incoming label: 1037 233 - outgoing label: 2048 234 - outgoing nhop: B 235 - Note: this entry is programmed by LDP for 192.0.2.203/32 237 Incoming label: 203 238 - outgoing label: 203 239 - outgoing nhop: B 240 - Note: this entry is programmed by SR for 192.0.2.203/32 242 These two entries can co-exist because their incoming label is 243 unique. The uniqueness is guaranteed by the label manager allocation 244 rules. 246 The same applies for the MPLS2IP forwarding entries. 248 2.2. IP2MPLS co-existence 250 By default, we propose that if both LDP and SR propose an IP2MPLS 251 entry for the same IP prefix, then the LDP route is selected. 253 A local policy on a router MUST allow to prefer the SR-provided 254 IP2MPLS entry. 256 3. Migration from LDP to SR 257 PE2 PE4 258 \ / 259 PE1----P5--P6--P7---PE3 261 Figure 2: Migration 263 Several migration techniques are possible. We describe one technique 264 inspired by the commonly used method to migrate from one IGP to 265 another. 267 T0: all the routers run LDP. Any service is tunneled from an ingress 268 PE to an egress PE over a continuous LDP LSP. 270 T1: all the routers are upgraded to SR. They are configured with the 271 SRGB range (100, 200). PE1, PE2, PE3, PE4, P5, P6 and P7 are 272 respectively configured with the node segments 101, 102, 103, 104, 273 105, 106 and 107 (attached to their service-recursing loopback). 275 At this time, the service traffic is still tunneled over LDP LSP. 276 For example, PE1 has an SR node segment to PE3 and an LDP LSP to 277 PE3 but by default, as seen earlier, the LDP IP2MPLS encapsulation 278 is preferred. 280 T2: the operator enables the local policy at PE1 to prefer SR IP2MPLS 281 encapsulation over LDP IP2MPLS. 283 The service from PE1 to any other PE is now riding over SR. All 284 other service traffic is still transported over LDP LSP. 286 T3: gradually, the operator enables the preference for SR IP2MPLS 287 encapsulation across all the edge routers. 289 All the service traffic is now transported over SR. LDP is still 290 operational and services could be reverted to LDP. 292 T4: LDP is unconfigured from all routers. 294 4. SR and LDP Interworking 296 In this section, we analyze a use-case where SR is available in one 297 part of the network and LDP is available in another part. We 298 describe how a continuous MPLS tunnel can be built throughout the 299 network. 300 PE2 PE4 301 \ / 302 PE1----P5--P6--P7--P8---PE3 304 Figure 3: SR and LDP Interworking 306 Let us analyze the following example: 308 P6, P7, P8, PE4 and PE3 are LDP capable. 310 PE1, PE2, P5 and P6 are SR capable. PE1, PE2, P5 and P6 are 311 configured with SRGB (100, 200) and respectively with node 312 segments 101, 102, 105 and 106. 314 A service flow must be tunneled from PE1 to PE3 over a continuous 315 MPLS tunnel encapsulation. We need SR and LDP to interwork. 317 4.1. LDP to SR 319 In this section, we analyze a right-to-left traffic flow. 321 PE3 has learned a service route whose nhop is PE1. PE3 has an LDP 322 label binding from the nhop P8 for the FEC "PE1". Hence PE3 sends 323 its service packet to P8 as per classic LDP behavior. 325 P8 has an LDP label binding from its nhop P7 for the FEC "PE1" and 326 hence P8 forwards to P7 as per classic LDP behavior. 328 P7 has an LDP label binding from its nhop P6 for the FEC "PE1" and 329 hence P7 forwards to P6 as per classic LDP behavior. 331 P6 does not have an LDP binding from its nhop P5 for the FEC "PE1". 332 However P6 has an SR node segment to the IGP route "PE1". Hence, P6 333 forwards the packet to P5 and swaps its local LDP-label for FEC "PE1" 334 by the equivalent node segment (i.e. 101). 336 P5 pops 101 (assuming PE1 advertised its node segment 101 with the 337 penultimate-pop flag set) and forwards to PE1. 339 PE1 receives the tunneled packet and processes the service label. 341 The end-to-end MPLS tunnel is built from an LDP LSP from PE3 to P6 342 and the related node segment from P6 to PE1. 344 4.2. SR to LDP 346 In this section, we analyze the left-to-right traffic flow. 348 We assume that the operator configures P5 to act as a Segment Routing 349 Mapping Server (SRMS) and advertise the following mappings: (P7, 350 107), (P8, 108), (PE3, 103) and (PE4, 104). 352 These mappings are advertised as Remote-Bundle SID with Flag TBD. 354 The mappings advertised by an SR mapping server result from local 355 policy information configured by the operator. IF PE3 had been SR 356 capable, the operator would have configured PE3 with node segment 357 103. Instead, as PE3 is not SR capable, the operator configures that 358 policy at the SRMS and it is the latter which advertises the mapping. 359 Multiple SRMS servers can be provisioned in a network for redundancy. 361 The mapping server advertisements are only understood by the SR 362 capable routers. The SR capable routers install the related node 363 segments in the MPLS data plane exactly like if the node segments had 364 been advertised by the nodes themselves. 366 For example, PE1 installs the node segment 103 with nhop P5 exactly 367 as if PE3 had advertised node segment 103. 369 PE1 has a service route whose nhop is PE3. PE1 has a node segment 370 for that IGP route: 103 with nhop P5. Hence PE1 sends its service 371 packet to P5 with two labels: the bottom label is the service label 372 and the top label is 103. 374 P5 swaps 103 for 103 and forwards to P6. 376 P6's next-hop for the IGP route "PE3" is not SR capable (P7 does not 377 advertise the SR capability). However, P6 has an LDP label binding 378 from that next-hop for the same FEC (e.g. LDP label 1037). Hence, 379 P6 swaps 103 for 1037 and forwards to P7. 381 P7 swaps this label with the LDP-label received from P8 and forwards 382 to P8. 384 P8 pops the LDP label and forwards to PE3. 386 PE3 receives the tunneled packet and processes the service label. 388 The end-to-end MPLS tunnel is built from an SR node segment from PE1 389 to P6 and an LDP LSP from P6 to PE3. 391 Note: contrary to Prefix-SID, SR mappings do not allow for Pen- 392 ultimate Hop Popping. In the previous example, P6 requires the 393 presence of the segment 103 such as to map it to the LDP label 1037. 394 For that reason, the P flag available in the Prefix-SID is not 395 available in the Remote-Bundle SID. 397 5. Leveraging SR benefits for LDP-based traffic 399 SR can be deployed such as to enhance LDP transport. The SR 400 deployment can be limited to the network region where the SR benefits 401 are most desired. 403 In Figure 4, let us assume: 405 All link costs are 10 except FG which is 30. 407 All routers are LDP capable. 409 X, Y and Z are PE's participating to an important service S. 411 The operator requires 50msec link-based FRR for service S. 413 A, B, C, D, E, F and G are SR capable. 415 X, Y, Z are not SR capable, e.g. as part of a staged migration 416 from LDP to SR, the operator deploys SR first in a sub-part of the 417 network and then everywhere. 419 X 420 | 421 Y--A---B---E--Z 422 | | \ 423 D---C--F--G 424 30 426 Figure 4: Leveraging SR benefits for LDP-based-traffic 428 The operator would like to resolve the following issues: 430 To protect the link BA along the shortest-path of the important 431 flow XY, B requires an RLFA repair tunnel to D and hence a 432 directed LDP session from B to D. The operator does not like these 433 dynamically established multi-hop LDP sessions and would seek to 434 eliminate them. 436 There is no LFA/RLFA solution to protect the link BE along the 437 shortest path of the important flow XZ. The operator wants a 438 guaranteed link-based FRR solution. 440 The operator can meet these objectives by deploying SR only on A, B, 441 C, D, E and F: 443 The operator configures A, B, C, D, E, F and G with SRGB (100, 444 200) and respective node segments 101, 102, 103, 104, 105, 106 and 445 107. 447 The operator configures D as an SR Mapping Server with the 448 following policy mapping: (X, 201), (Y, 202), (Z, 203}. 450 Each SR node automatically advertises local adjacency segment for 451 its IGP adjacencies. Specifically, F advertises adjacency segment 452 9001 for its adjacency FG. 454 A, B, C, D, E, F and G keep their LDP capability and hence the flows 455 XY and XZ are transported over end-to-end LDP LSP's. 457 For example, LDP at B installs the following MPLS data plane entries: 458 Incoming label: local LDB label bound by B for FEC Y 459 Outgoing label: LDP label bound by A for FEC Y 460 Outgoing nhop: A 461 Incoming label: local LDB label bound by B for FEC Z 462 Outgoing label: LDP label bound by E for FEC Z 463 Outgoing nhop: E 465 The novelty comes from how the backup chains are computed for these 466 LDP-based entries. While LDP labels are used for the primary nhop 467 and outgoing labels, SR information is used for the FRR construction. 468 In steady state, the traffic is transported over LDP LSP. In 469 transient FRR state, the traffic is backup thanks to the SR enhanced 470 capabilities. 472 This helps meet the requirements of the operator: 474 Eliminate directed LDP session. 476 Guaranteed FRR coverage. 478 Keep the traffic over LDP LSP in steady state. 480 Partial SR deployment only where needed. 482 5.1. Eliminating Directed LDP Session 484 B's MPLS entry to Y becomes: 485 - Incoming label: local LDB label bound by B for FEC Y 486 Outgoing label: LDP label bound by A for FEC Y 487 Backup outgoing label: SR node segment for Y {202} 488 Outgoing nhop: A 489 Backup nhop: repair tunnel: node segment to D {104} 490 with outgoing nhop: C 492 In steady-state, X sends its Y-destined traffic to B with a top label 493 which is the LDP label bound by B for FEC Y. B swaps that top label 494 for the LDP label bound by A for FEC Y and forwards to A. A pops the 495 LDP label and forwards to Y. 497 Upon failure of the link BA, B swaps the incoming top-label with the 498 node segment for Y (202) and sends the packet onto a repair tunnel to 499 D (node segment 104). Thus, B sends the packet to C with the label 500 stack {104, 202}. C pops the node segment 104 and forwards to D. D 501 swaps 202 for 202 and forwards to A. A's nhop to Y is not SR capable 502 and hence A swaps the incoming node segment 202 to the LDP label 503 announced by its next-hop (in this case, implicit null). 505 After IGP convergence, B's MPLS entry to Y will become: 506 - Incoming label: local LDB label bound by B for FEC Y 507 Outgoing label: LDP label bound by C for FEC Y 508 Outgoing nhop: C 510 And the traffic XY travels again over the LDP LSP. 512 Conclusion: the operator has eliminated its first problem: directed 513 LDP sessions are no longer required and the steady-state traffic is 514 still transported over LDP. The SR deployment is confined to the 515 area where these benefits are required. 517 5.2. Guaranteed FRR coverage 519 B's MPLS entry to Z becomes: 521 - Incoming label: local LDB label bound by B for FEC Z 522 Outgoing label: LDP label bound by E for FEC Z 523 Backup outgoing label: SR node segment for Z {203} 524 Outgoing nhop: E 525 Backup nhop: repair tunnel to G: {106, 9001} 527 G is reachable from B via the combination of a 528 node segment to F {106} and an adjacency segment 529 FG {9001} 531 Note that {106, 107} would have equally work. 532 Indeed, in many case, P's shortest path to Q is 533 over the link PQ. The adjacency segment from P to 534 Q is required only in very rare topologies where 535 the shortest-path from P to Q is not via the link 536 PQ. 538 In steady-state, X sends its Z-destined traffic to B with a top label 539 which is the LDP label bound by B for FEC Z. B swaps that top label 540 for the LDP label bound by E for FEC Z and forwards to E. E pops the 541 LDP label and forwards to Z. 543 Upon failure of the link BE, B swaps the incoming top-label with the 544 node segment for Z (203) and sends the packet onto a repair tunnel to 545 G (node segment 106 followed by adjacency segment 9001). Thus, B 546 sends the packet to C with the label stack {106, 9001, 203}. C pops 547 the node segment 106 and forwards to F. F pops the adjacency segment 548 9001 and forwards to G. G swaps 203 for 203 and forwards to E. E's 549 nhop to Z is not SR capable and hence E swaps the incoming node 550 segment 203 for the LDP label announced by its next-hop (in this 551 case, implicit null). 553 After IGP convergence, B's MPLS entry to Z will become: 554 - Incoming label: local LDB label bound by B for FEC Z 555 Outgoing label: LDP label bound by C for FEC Z 556 Outgoing nhop: C 558 And the traffic XZ travels again over the LDP LSP. 560 Conclusion: the operator has eliminated its second problem: 561 guaranteed FRR coverage is provided. The steady-state traffic is 562 still transported over LDP. The SR deployment is confined to the 563 area where these benefits are required. 565 6. Inter-AS Option C, Carrier's Carrier and Seamless MPLS 566 PE1---R1---B1---B2---R2---PE2 567 <-----------> <-----------> 568 AS1 AS2 570 Figure 5: Inter-AS Option C 572 In Inter-AS Option C [RFC4364], B2 advertises to B1 a BGP3107 route 573 for PE2 and B1 reflects it to its internal peers, such as PE1. PE1 574 learns from a service route reflector a service route whose nhop is 575 PE2. PE1 resolves that service route on the BGP3107 route to PE2. 576 That BGP3107 route to PE2 is itself resolved on the AS1 IGP route to 577 B1. 579 If AS1 operates SR, then the tunnel from PE1 to B1 is provided by the 580 node segment from PE1 to B1. 582 PE1 sends a service packet with three labels: the top one is the node 583 segment to B1, the next-one is the BGP3107 label provided by B1 for 584 the route "PE2" and the bottom one is the service label allocated by 585 PE2. 587 The same straightforward SR applicability is derived for CsC and 588 Seamless MPLS ([I-D.ietf-mpls-seamless-mpls]). 590 7. IANA Considerations 592 TBD 594 8. Manageability Considerations 596 TBD 598 9. Security Considerations 600 TBD 602 10. Acknowledgements 604 We would like to thank Pierre Francois and Ruediger Geib for their 605 contribution to the content of this document. 607 11. References 608 11.1. Normative References 610 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 611 Requirement Levels", BCP 14, RFC 2119, March 1997. 613 [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private 614 Networks (VPNs)", RFC 4364, February 2006. 616 11.2. Informative References 618 [I-D.filsfils-rtgwg-segment-routing] 619 Filsfils, C., Previdi, S., Bashandy, A., Decraene, B., 620 Litkowski, S., Horneffer, M., Milojevic, I., Shakir, R., 621 Ytti, S., Henderickx, W., Tantsura, J., and E. Crabbe, 622 "Segment Routing Architecture", 623 draft-filsfils-rtgwg-segment-routing-00 (work in 624 progress), June 2013. 626 [I-D.ietf-mpls-seamless-mpls] 627 Leymann, N., Decraene, B., Filsfils, C., Konstantynowicz, 628 M., and D. Steinberg, "Seamless MPLS Architecture", 629 draft-ietf-mpls-seamless-mpls-04 (work in progress), 630 July 2013. 632 [draft-filsfils-rtgwg-segment-routing-mpls-00] 633 Filsfils, C. and S. Previdi, "Segment Routing with MPLS 634 data plane", October 2013. 636 Authors' Addresses 638 Clarence Filsfils (editor) 639 Cisco Systems, Inc. 640 Brussels, 641 BE 643 Email: cfilsfil@cisco.com 645 Stefano Previdi (editor) 646 Cisco Systems, Inc. 647 Via Del Serafico, 200 648 Rome 00142 649 Italy 651 Email: sprevidi@cisco.com 652 Ahmed Bashandy 653 Cisco Systems, Inc. 654 170, West Tasman Drive 655 San Jose, CA 95134 656 US 658 Email: bashandy@cisco.com 660 Bruno Decraene 661 Orange 662 FR 664 Email: bruno.decraene@orange.com 666 Stephane Litkowski 667 Orange 668 FR 670 Email: stephane.litkowski@orange.com 672 Martin Horneffer 673 Deutsche Telekom 674 Hammer Str. 216-226 675 Muenster 48153 676 DE 678 Email: Martin.Horneffer@telekom.de 680 Igor Milojevic 681 Telekom Srbija 682 Takovska 2 683 Belgrade 684 RS 686 Email: igormilojevic@telekom.rs 688 Rob Shakir 689 British Telecom 690 London 691 UK 693 Email: rob.shakir@bt.com 694 Saku Ytti 695 TDC Oy 696 Mechelininkatu 1a 697 TDC 00094 698 FI 700 Email: saku@ytti.fi 702 Wim Henderickx 703 Alcatel-Lucent 704 Copernicuslaan 50 705 Antwerp 2018 706 BE 708 Email: wim.henderickx@alcatel-lucent.com 710 Jeff Tantsura 711 Ericsson 712 300 Holger Way 713 San Jose, CA 95134 714 US 716 Email: Jeff.Tantsura@ericsson.com 718 Edward Crabbe 719 Google, Inc. 720 1600 Amphitheatre Parkway 721 Mountain View, CA 94043 722 US 724 Email: edc@google.com